Output Feedback Based 2DOF Control with a Robust Predictive Feedforward Input

This paper deals with a two degree of freedom control system design problem based on the ASPR-based output feedback with a predictive control as a feedforward input. It is well known that one can design a stable output feedback control system with a high gain feedback if the considered controlled system satisfies almost strictly positive real (ASPR) conditions. Unfortunately, however, the ASPR conditions impose a severe restriction to the controlled systems. The introduction of a parallel feedforward compensator is one of the simple strategies to alleviate the ASPR restrictions. In this paper, we propose an output tracking control system design scheme for ASPR augmented systems with the PFC by applying a predictive control input as a feedforward input. A robust design scheme of an output predictor for the proposed predictive feedforward control will also be provided.